1. Field of the Invention
The present invention relates to a curtain wall insulation system which insulates adjacent floors. More specifically, the present invention relates to an interlocking curtain wall insulation which inhibits spread of fire from one floor to an upper adjacent floor through perimeter voids between an edge of a floor slab and the exterior building structure.
2. Description of the Related Art
Building structures utilize constructions combining steel, to provide a skeletal structure for the building, and concrete to provide floor structure. Accordingly, concrete is poured, or positioned in preformed slabs, from one side of the building to an opposed side. At interfaces between the concrete floor and exterior walls of the building, the perimeter voids are provided so that the building structure may be formed square and aesthetically pleasing, even though the concrete slab may not be. The perimeter voids provide an indirect advantage in that they accommodate for the difference in thermal expansion between the structural steel and the concrete floor slab.
However, providing such a perimeter void presents problems in fire retardance and suppression. During fires in building structures of the type previously described, the aforementioned perimeter voids provide a means for air movement between floors and act as a flue for the rise of hot gas during fire conditions. More problematic is the spread of flames and hot gases from one floor to another through the perimeter voids which consequently allow fire to spread throughout a building.
Various designs have been contemplated in order to inhibit the spread of fire throughout a building. For example, one design comprises a trough device disposed within the thermal expansion gap wherein the trough is filled with urea formaldehyde foam. However this design fails to provide means to interconnect the trough and curtain wall on the outside edge of the trough. Thus air gaps may form between the trough and curtain wall allowing the rise of smoke, flames, and hot gases. Alternatively, fire insulation, or safing insulation as it is typically termed, has been positioned in the thermal expansion gap between the curtain wall and floor slab. However, since the curtain wall structure is typically held in place by aluminum, during fire conditions, the aluminum structure can weaken or melt allowing the curtain wall to move slightly and further allowing the safing insulation to fall from its position between the floor slab and curtain wall.
Given the foregoing deficiencies, it will be appreciated that an interlocking curtain wall insulation system is needed which is held in place by interconnection with alternate parts of the curtain wall system so that the perimeter voids are closed inhibiting the spread of flame and hot gases.